Breath analysis is a potential revolution in lung and other disease diagnostics since the collection of exhaled breath is a safe, non-invasive, easy and simple procedure and each individual can provide breath that contains information regarding their own internal state.
Cystic Fibrosis (CF) is the most common genetic disorder in the white population, affecting 1 in 3300 live Caucasian births. This genetic disorder disables a transmembrane chloride conductance regulator (CFTR) that regulates the balance of salts in epithelia cells that exist in many of the glands and affects multiple systems, including lung, pancreas, and gastrointestinal systems. In lung disease, deficiency in CFTR causes obstruction of submucosal glands and distal airways with thick tenacious secretions against bacterial infection. Bacteria that most often colonize and infect the lungs of people with CF are Haemophilus influenza, Staphylococcus, and Pseudomonas aeruginosa (P. aeruginosa) and among these three, Pseudomonas family has a reputation of being particularly dangerous, which correlates with declining lung function and high mortality rates.
Pseudomonas aeruginosa is a Gram negative bacterium that produces an odor (grape-like) which has been identified as 2-aminoacetophenone (2-AA). This compound was once detected in the headspace of Escherichia coli (E. coli) cultures, but not in other respiratory pathogens and, therefore, was used as a volatile biomarker for infection and/or colonization in the lung. However, 2-AA was also found in the breath samples of uninfected individuals shortly after eating certain foods, such as corn, dairy, honey products and wine. Other than 2-AA, 2-nonanone, 2,4-dimethyl-1-heptene, 1-heptene, isopentanol and limonene have been found in the headspace of spontaneously expectorated sputum with P. aeruginosa. 
Headspace samplers are used to introduce a portion of the headspace gas present over any type of sample, either gas, liquid or solid, confined in a closed system, such as a sealed vial. The vial can be maintained at room or any other temperature to establish an equilibrium composition of volatiles above the sample. Advantageously, headspace sampling allows the selective sampling of volatile species while leaving the complex matrix in the vial without contamination during sampling. Although headspace sampling is useful for analysis of samples from a complicated matrix, the low concentration of components in a headspace and the small sample volume can be problematic for detection of trace compounds.
Hence, although the headspace sampling over P. aeruginosa can be carried out by headspace analysis, a consistent and sensitive protocol for the detection of P. aeruginosa where the identification of the specific strain remains a goal that can aid in the treatment of the disorder.